Re: git: 4dbc7835cdfc - main - mips: Turn off LLVM MIPS targets by default

On 12/14/21 11:09 AM, Warner Losh wrote:
> On Tue, Dec 14, 2021 at 11:57 AM John Baldwin <jhb@freebsd.org> wrote:
> 
>> On 12/14/21 10:42 AM, Ed Maste wrote:
>>> On Tue, 14 Dec 2021 at 13:27, John Baldwin <jhb@freebsd.org> wrote:
>>>>
>>>> This breaks NO_CLEAN=yes builds in I think a lot of object files.
>>>> ...
>>>> Perhaps we should be generating those header files in OBJDIR (and use a
>> move-if-changed
>>>> scheme to avoid bumping the date if the contents haven't changed) so
>> that make can handle
>>>> these changes?
>>>
>>> Seems reasonable if that change is straightforward, but we could also
>>> just add a special case in tools/build/depend-cleanup.sh to handle
>>> this. depend-cleanup can be fairly liberal, e.g. delete *.def.
>>
>> Yes, but the problem isn't deleting *.def.  Those are static files whose
>> content
>> changes based on -D flags passed on the command line and you need to
>> delete all
>> the *.o files that include those .def files.  Note that if you switch from
>> WITHOUT_LLVM_TARGET_ALL to WITH_LLVM_TARGET_ALL or vice versa between
>> builds
>> you would also hit this issue.
>>
> 
> True that. Hence my desire to move these into a file that changes when the
> option changes :)
> 
> If there's some cheap hack I can do to fix this, I'm open to suggestions. I
> just don't want to spend
> a day futzing with it since I have other things I'm trying to get done this
> week....

I don't know that we have a cheap way to do this.  Maybe dim@ is willing to
look at generating those files?  We'd want a move-if-change wrapper around
them though which is not something we currently do for generated files.

-- 
John Baldwin